JP2011137497A - Rack and pinion mechanism and vacuum treatment device with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rack and pinion mechanism smoothly meshing a rack gear with a pinion gear with a simple mechanism dispensing with a synchronously driving means, and a vacuum treatment device with the same. <P>SOLUTION: This rack and pinion mechanism includes the rack gear fixed on a placing base carrying a carrying object and moving on a conveyance track, and a plurality of the pinion gears connected to a driving source and meshed with the rack gear. The rack gear is delivered from the pinion gear in the present process to the pinion gear in the next process, and the placing base is conveyed, and a tooth top of the rack gear fixed on the placing base is different from other tooth tops at least in one part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rack and pinion mechanism as a transport mechanism and a vacuum processing apparatus including the same.

  The rack-and-pinion mechanism is a mechanism that combines a pinion gear and a rack gear toothed in the width direction on one side of a square bar, and converts the rotation of the pinion gear into a linear movement of the rack gear. Etc. are used.

  For example, in a vacuum processing apparatus such as an inline sputtering apparatus, a substrate tray for holding a substrate is sequentially transported by a carrier with a rack and transferred between the vacuum processing chambers to be transferred to the next process, and a desired process is performed on the substrate. . That is, the rack gear is fixed to the substrate tray, the rack gear is engaged with the pinion gear provided in each vacuum processing chamber, and the rack gear is rotationally driven, and sequentially transferred to the pinion gear of the vacuum processing chamber in the next process, thereby transferring the substrate tray. Yes.

FIG. 4 is a plan view schematically showing an example of a vacuum processing apparatus having a plurality of vacuum processing chambers.
A plurality of vacuum processing chambers 10 having various functions are connected to the vacuum processing apparatus shown in FIG. In the vacuum processing apparatus, for example, three direction change chambers 18 are connected in series via a gate valve 14, and each direction change chamber 18 includes a carrier (mounting table) rotation mechanism (turntable) 22 described later. It has been.

  In addition, two or three vacuum processing chambers 10 are connected around the direction change chambers 18 via gate valves 14, respectively. The vacuum processing chamber 10 is configured by, for example, a sputtering film forming chamber, but is not limited thereto, and may be a processing chamber that performs only heating or cooling.

  For example, an intermediate chamber 19 as a spare chamber is connected to one of the three direction changing chambers 18 via a gate valve 14. The intermediate chamber 19 is connected via a gate valve 14 to two load lock chambers 21 for stocking the substrate and for taking in and out the substrate between the vacuum space and the atmosphere. These rooms are partitioned as vacuum spaces, and each has a transport track (reference numeral 36 is the direction of carrier movement), which will be described later.

FIG. 5 is a front view schematically showing a state in which the vacuum processing chamber 10 is viewed from the transport direction of the vacuum processing apparatus 10 shown in FIG. 4.
In the center of the bottom surface of the vacuum processing chamber 10 (sputtering film forming chamber in FIG. 4), a transport track 7 that defines the transport direction is laid.
A plurality of bearings 6 serving as guide members are supported on the transport track 7 along the track. These bearings 6 support the carrier 20, and the bearings 6 are engaged with concave support portions 5 formed on the lower surface of the carrier 20.

That is, the carrier 20 moves on the transport track 7 while being supported by the bearing 6 and guided.
At this time, the weight of the entire carrier 20 reaches, for example, about 200 kg or more. However, since the carrier 20 has a self-supporting structure that is symmetrical with respect to the width direction of the transport track 7, it is stably supported by the bearing 6.

  On the carrier 20, for example, substrate trays 4 a and 4 b for holding two substrates 3 are provided in an upright state as the objects to be conveyed. The substrate 3 is composed of, for example, a glass substrate or the like, and is held by the substrate trays 4a and 4b so as to face each other in opposite directions. In the preparation chamber (not shown), the substrate trays 4 a and 4 b are inclined and the two substrates 3 are attached to the carrier 20. Although the substrate trays 4a and 4b for holding the substrate 3 are arranged on both sides of the carrier 20 in FIG. 5, only one side may be used. The substrate 3 is held on the carrier 20 while being pressed on four sides by, for example, fixing jigs (not shown) attached to the four sides of the substrate trays 4a and 4b.

Each vacuum processing chamber 10 is connected to an exhaust device 11 that exhausts the inside.
For example, the vacuum processing chamber 10 is evacuated to about 2 × 10 Pa to 2 × 10 ⁻⁵ Pa by the exhaust device 11. Further, gas supply devices 9 a and 9 b for supplying a processing gas to the inside are connected to each vacuum processing chamber 10.

Further, the targets 16 are respectively arranged so as to face the substrate 3, and the targets 16 are supported on the backing plate 17 in an upright state.
A magnet unit (not shown) for generating a closed loop magnetic field on the surface of the target 16 is provided on the back side of the backing plate 17. Further, the upper and lower sides of the space between the substrate 3 and the target 16 are covered with the shield member 12.

  As described above, an example of a vacuum processing apparatus of an in-line sputtering apparatus used in the production of a PDP or the like that transports a large substrate is shown in FIGS. 4 and 5. -The following problems to be solved remained in the pinion mechanism.

  That is, between the vacuum processing chambers of the vacuum processing apparatus, when the pinion gear 100 of the current process is transferred to the pinion gear 100 of the next process and meshed, the tooth tips of the rack gear and the pinion gear may collide with each other.

FIG. 6 is a schematic diagram showing a meshing relationship between the conventional rack gear 200 and the pinion gear 100. Further, the respective tooth tips are indicated by reference numerals 42 and 41, and the moving directions are indicated by 38 and 39, respectively.
When the tooth tips 41 and 42 collide with each other, a load is applied and the drive mechanism is damaged, or the tooth tip 42 of the rack gear 200 rides on the tooth tip 41 of the pinion gear 100 so that it cannot be conveyed, or the normal meshing occurs. There was a product failure due to breakage of the substrate or dust generation due to a collision or impact when returning.

  In order to solve such problems, techniques have been proposed in which a one-way clutch is provided or the pinion gear escapes in a direction perpendicular to the pinion shaft or in the axial direction. These techniques have been created from the idea of automatically returning to normal meshing even if there is a collision between tooth tips (see, for example, Patent Document 1).

  Further, a technique has been proposed in which the stop angle of the pinion gear is accurately managed by a sensor and a control mechanism, and the rack gear is engaged without colliding with the tooth tip of the pinion gear.

In addition, a rack and pinion mechanism has been proposed in which the phase of the pinion gear is adjusted to the rack gear in advance by mechanical means (see, for example, Patent Document 2).
Specifically, this mechanism supports the spherical member with a spring and presses it against the recess of the cam to set the stop angle of the pinion shaft to a predetermined position, and before the pinion gear and the rack gear mesh with each other, the pinion guide and the rack The phase is adjusted with a guide. According to this configuration, the rack gear and the pinion gear can be engaged with each other without causing a collision between the tooth tips.

  Furthermore, a transport device is proposed that includes a plurality of stepping motor driven pinion gears that are provided in the longitudinal direction and at least one of which is arranged to mesh with a rack gear, and synchronous driving means that synchronously drives at least two pinion gears. (For example, refer to Patent Document 3).

JP 11-247957 A JP-A-8-74661 Japanese Patent Laid-Open No. 9-291360

  The conventional technique of providing a one-way clutch and the technique of releasing a pinion gear are ideas that attempt to restore the normal meshing without correcting the phase relationship between the rack gear and the pinion gear at the beginning. Therefore, the collision between the rack gear and the pinion gear cannot be avoided in the first place, and there is a possibility that the tooth tip may be damaged.

  Further, when the clutch is provided, the movement direction of the rack gear is limited to one direction. The technology for escaping the pinion gear requires an intermediate gear, so that the installation space increases and the sliding portion increases, resulting in a mechanical complexity.

  According to the technique of Patent Document 2, the stop position of the pinion gear can be managed based on the positional relationship between the spherical member supported by the spring and the cam, and in principle, the tooth tips collide between the rack gear and the pinion gear. Has the advantage of not. However, when the rotational driving force is transmitted at a high speed with respect to the rotation of the pinion gear, the accuracy of the rotation stop angle is limited by the mechanical structure portion. Therefore, the pinion gear cannot always be stopped at a fixed position, and the mechanical structure portion is rattled and further friction occurs. Therefore, there is a problem that the adjustment of the mechanical structure portion must always be repeated.

  In addition, the technology for managing the stop position of the pinion gear by the sensor and the control mechanism is considered to be none in principle because the engagement is allowed after the phases of the pinion gear and the rack gear are completely matched. However, considering application to a vacuum processing apparatus in particular, some of these apparatuses perform high-temperature processing up to about 400 ° C., and it has become necessary to consider the influence of heat from the sensor and the like, the thermal expansion of the rack gear, and the like.

  According to the technique of Patent Document 3, at least two pinion gears are synchronously driven by synchronous driving means, and control is performed to synchronize before the rack gear meshes with the pinion gear of the next process. However, it can be said that the pinion gear teeth do not hit the rack gear teeth at all.If the pinion gear teeth hit, the motor torque value increases and an overload error occurs or the teeth are damaged. The transportation could not be continued.

  An object of the present invention is to provide a rack and pinion mechanism that can smoothly mesh a rack gear and a pinion gear with a simple mechanism that does not require synchronous drive means, and a vacuum processing apparatus including the same. It is in.

  The configuration of the present invention made to achieve the above object is as follows.

The rack and pinion mechanism according to the present invention for achieving the above object includes a rack gear fixed to a mounting table on which an object to be transported is mounted and moved on a transport track, and is connected to a drive source and meshes with the rack gear. A plurality of pinion gears,
The rack gear is transferred from the pinion gear of the current process to the pinion gear of the next process and conveyed to the mounting table, and the tooth tips of the rack gear fixed to the mounting table are different from other tooth tips at at least one location. It is characterized by.

Further, in the vacuum processing apparatus of the present invention for achieving the above object, the object to be transported is a substrate, and includes the rack and pinion mechanism as a transport mechanism of the mounting table,
A plurality of vacuum processing chambers are connected along the transport track, and one or more of the rack and pinion mechanisms are provided in the vacuum processing chambers.

  According to the present invention, since the rack gear and the pinion gear can be smoothly meshed with a simple mechanism that does not require the synchronous driving means, the transport reliability can be improved.

It is the schematic which shows typically the carrier which has arrange | positioned the rack and pinion mechanism which concerns on embodiment of this invention. It is a schematic diagram which shows the meshing relationship of the rack and pinion mechanism which concerns on embodiment of this invention. It is an enlarged view of the rack gear which concerns on embodiment of this invention. It is a top view which shows typically one Embodiment of the vacuum processing apparatus provided with the several vacuum processing chamber. It is a front view which shows typically the conventional vacuum processing chamber seen from the conveyance direction. It is a schematic diagram which shows the meshing relationship of the conventional rack gear and pinion gear.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2, and 3. In FIG. 1, elements that are substantially the same as those described in FIG. 5 are denoted by the same reference numerals.

With reference to FIG. 1, the rack and pinion mechanism as the carrier transport mechanism of the vacuum processing apparatus will be described.
FIG. 1 is a schematic view further schematically showing a rack and pinion mechanism when the vacuum processing chamber 10 shown in FIG. 5 is viewed from the direction of reference numeral 3 on the side surface side.

As shown in FIG. 1, on one side of the lower surface of the carrier 20, which is a mounting table that is partially omitted, one surface of a square bar material called a rack gear 2 according to the present invention is toothed in the width direction. The linear gear is disposed along the conveyance direction 31 with the gear portion facing downward. The pinion gear 1 is provided in each vacuum processing chamber and is rotated by a driving force of a driving source (not shown) such as a servo motor disposed on the atmosphere side via a pinion driving device 15 including a plurality of intermediate gears.
At least two of the plurality of pinion gears 1 are rotated and meshed sequentially with the rack gear 2 so that the rack gear 2 is transferred from the pinion gear 1 in the current process to the pinion gear 1 in the next process.

Here, the rack gear 2 according to the present invention is characterized in that, although the tooth profile of the standard reference rack gear is usually determined, the tooth tip is different from other tooth tips at at least one location.
FIG. 1 shows that the tooth tip of the rack gear is different in shape from the other tooth tips at both ends thereof.

That is, the carrier 20 to which the rack and pinion mechanism according to the present invention shown in FIG. 1 is fixed can move forward and backward on the transport track 7 as indicated by the transport direction 31. The shape of the rack gears at both ends in contact with the other rack gears are different from each other.
Therefore, if the carrier 20 is restricted to advance in one direction, the rack gear only needs to have the tip of the leading tooth on one side different from the other tip.

FIG. 2 is a schematic diagram showing the meshing relationship of the rack and pinion mechanism according to the present invention.
In FIG. 2, the rack gear 2 moves in the direction of reference numeral 33, the pinion gear 1 rotates in the direction of reference numeral 34, and the moment when the leading tooth tip of one side of the rack gear 2 just contacts the tooth tip 43 of the pinion gear is shown. Has been.
At this time, the top tooth tip of one side of the rack gear 2 has a different shape from the other tooth tips 42, and in order to reduce the probability of riding on the tooth tips 43 of the pinion gear 1, the top of the tooth tips 43 is directed in the direction of reference numeral 35. It is easy to slip. As shown in FIG. 2, if the pinion 1 side is processed by narrowing the tooth tip 43 by chamfering or the like, the effect can be further improved.

  As described above, the difference in the shape of the tooth tip is not limited to changing the width of the tooth tip (hereinafter also referred to as the tooth tip width) by chamfering or the like as described above, and may further be subjected to R processing.

Here, the clearance between the pinion gear 1 and the rack gear 2 (the distance between the end surfaces of each tooth) is 0.35 to the module of the pinion gear 1 (the size of the teeth expressed in millimeters). A value multiplied by a coefficient of 0.4 is preferred.
For example, in a rack and pinion mechanism using the pinion gear of module 4, the clearance is preferably about 1.5 mm.
In FIG. 2, the tooth tip 44 of the second tooth after the one-side head tooth of the rack gear 2 is also processed with a narrower width than the tooth tip 42.

FIG. 3 is an enlarged view of the rack gear according to the embodiment of the present invention.
In FIG. 3, reference numeral 32 represents the moving direction of the rack gear 2 according to the present invention, and reference numeral 50,
Reference numerals 51, 52, 53, 54, and 55 represent features of the shape of the rack gear 2 according to the present invention. Reference line 50, pressure angle 51, tooth tips 52 and 53, and normal lines of the reference line, respectively. 55.

The reference line 50 is a line indicating a half position with respect to the depth of the teeth meshing with the counter gear, and the pressure angle 51 indicates an angle at which the teeth are inclined with respect to the normal line of the reference line 50.
The tooth tip 52 is a tooth on one side of both ends of the rack gear 2 according to the present invention.
Further, the tooth tip 53 is a tooth tip other than both ends of the rack gear 2, but the tooth tip width is wider than the tooth tip 52 (the tooth tip 52 is processed to be narrower than the tooth tip 53).
In this way, the rack gear and the pinion gear can be smoothly meshed only by processing at least one position of the rack gear, and the reliability of transporting the carrier or the like can be improved.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to said embodiment, A various change is possible in the technical range grasped | ascertained from description of a claim.

DESCRIPTION OF SYMBOLS 1,100 Pinion gear 2,200 Rack gear 3 Substrate 4a, 4b Substrate tray 5 Concave support 6 Bearing 7 Transport track 9a, 9b Gas supply device 10 Vacuum processing chamber 11 Exhaust device 14 Gate valve 15 Pinion drive device 16 Target 17 Backing plate 18 Direction change room 19 Intermediate room 20 Carrier (mounting table)
21 Load lock chamber 22 Rotating mechanism (turntable)
31 Rack gear transport direction 32, 33 Rack gear movement direction 34 Pinion gear rotation direction 35 Rack gear tooth tip movement
37 Side direction of the vacuum processing chamber 38 Rack gear movement direction 39 Pinion gear rotation direction 41 Pinion gear tooth tips 42 Rack gear tooth tips 43 Pinion gear tooth tips 44 Rack gear tooth tips 50 Reference line 51 Pressure angle 52 Tooth tips 53 Tooth tips 55 Normal of reference line

Claims (7)

A rack gear fixed to a mounting table on which an object to be conveyed is moved and moved on a conveyance track; and a plurality of pinion gears coupled to a drive source and meshing with the rack gear; A rack-and-pinion mechanism that delivers the above-mentioned mounting table to the process pinion gear,
A rack and pinion mechanism characterized in that a tooth tip of the rack gear fixed to the mounting table is different from other tooth tips at at least one point.   The rack-and-pinion mechanism according to claim 1, wherein the rack gear has different tooth tips at both ends of the rack gear.   The rack and pinion mechanism according to claim 1, wherein the rack gear has different tooth tips on one side of both ends of the rack gear.   The rack-and-pinion mechanism according to any one of claims 1 to 3, wherein the difference between the tooth tips of the rack gear is a difference in pressure angle.   The rack-and-pinion mechanism according to any one of claims 1 to 4, wherein a difference in tooth tips of the rack gear is a difference in tooth tip width.   The rack and pinion mechanism according to any one of claims 1 to 5, wherein the rack gear is rounded. The substrate to be transported is a substrate, and includes the rack and pinion mechanism according to any one of claims 1 to 6 as a transport mechanism of the mounting table.
A vacuum processing apparatus, wherein a plurality of vacuum processing chambers are connected along the transfer track, and one or more of the rack and pinion mechanisms are provided in the vacuum processing chambers.